REVIEW: FINAL EXAM
1. Which of the following does not represent an increase in entropy?
(a) a solid melting
(c) a solute being dissolved in a solvent
(b) a gas changing to a liquid
(d) water being heated
2. In the reaction Mg + Cu+2 (aq)  Cu +
a) Mg
b) Cu+2
Mg+2 (aq), the oxidizing agent is
c) Mg+2
d) Cu
3. Given the reaction 2Cr + 3Cu2+ --> 3Cu + 2Cr3+ what is the net potential (Eo) for the reaction?
(a) 0.40 V
(c) 0.46 V
(b) 1.08 V
(d) 2.50 V
4. Which of the following invariably shifts a system at equilibrium to the right?
a) increasing pressure
b) removal of some product
c) addition of a catalyst
d) decreasing temperature
5. Which gaseous product is formed when dilute nitric acid reacts with silver metal in the absence of air?
(A)H2
(B)O2
(C)NH3
(D)NO
6. A 65.25 g sample of CuSO4•5H2O (M = 249.7) is dissolved in enough water to make 0.800 L of solution. What
volume of this solution must be diluted with water to make 1.00 L of 0.100 M CuSO4?
(A) 3.27 mL
(B) 81.6 mL
(C) 209 mL
(D) 306 mL
7. How many moles of O2 are required for the complete combustion of 2.2 g of C3H8 to form CO2 and H2O?
(A)0.050
(B)0.15
(C)0.25
(D)0.50
8. In the titration of a monoprotic acid with a solution of sodium hydroxide of known concentration, what quantities are
equal at the equivalence point?
(A) the concentrations of hydroxide and hydronium ions
(B) the number of moles of hydroxide ion added and the number of moles of hydronium ion initially present
(C) the volume of sodium hydroxide solution added and the volume of acid solution initially present
(D) the number of moles of hydroxide ion added and the number of moles of monoprotic acid initially present
9. When a nonvolatile solute is dissolved in a volatile solvent, which characteristic is greater for the solution than for the
solvent?
(A)boiling point
(B)freezing point
(C)rate of evaporation
(D)vapor pressure
10. A chemical reaction is most likely to occur spontaneously if the:
(a) free energy change(G) is negative
(c) activation energy is positive
(b) entropy change(S) is negative
(d) heat of reaction(H) is positive
11. A 30 milliliter sample of NaOH is completely neutralized by 10 milliliters of 1.5 M HCl. What is the molarity of the
NaOH solution?
a) 0.25 M
b) 0.50 M
c) 1.5 M
d) 4.5 M
12. When a crystal is added to a solution and additional crystals immediately form,the original solution was
a) unsaturated
b) a colloidal dispersion
c) saturated
d) at the triple point
e) supersaturated
13. A sample of gas occupies a volume of 9.23 L at 345 K and 1.40 atm. What is its volume at 525 K and 3.20 atm?
(A)2.65 L
(B)6.14 L
(C)13.9 L
(D)32.1 L
14. Which one of the following sets of conditions would result in a reaction that is spontaneous at high temperatures but
non-spontaneous at low temperatures?
(A) ΔH > 0, ΔS > 0
(B) ΔH > 0, ΔS < 0
(C) ΔH < 0, ΔS < 0
(D) ΔH < 0, ΔS > 0
15. Given the balanced reaction: 3H2 + N2  2NH3 + 92.2 kJ , how many grams of NH3 must be produced in order to
liberate 184.4 kJ?
a) 17.0 g
b) 34.0 g
c) 68.0 g
d)136.0 g
16. Which of the following is an example of a redox reaction?
a) HCl + KOH  KCl + H2O
b) CaCO3  CaO + CO2
c) C + H2O  CO + H2
d) BaCl2 + Na2SO4  BaSO4 + 2 NaCl
17. The oxidation number of Mn atom in the compound KMnO4 is equal to:
(a) -2
(c) +5
(b) +1
(d) +7
18. A substance has an empirical formula of C3H5 and a molecular mass of 410 g/mol. Its molecular formula is:
a) C3H5
b) C15H25
c) C30H50
d) C33H55
19. The percent by mass of oxygen in MgO is closest to
a) 16 %
b) 24 %
c) 40 %
d) 60 %
20. In the reaction: 2Na (s) + S (s)  Na2S (s), sulfur is:
a) oxidized
b) reduced
c) melted
d) neutralized
21. What is the total number of molecules contained in 45 grams of NO?
23
a) 1.0
b) 2.0
c) 6.0 x 10
22. When a neutral atom undergoes reduction, its oxidation number
a) decreases
b) increases
d) 9.0 x 10
23
c) remains the same
23. The published value for the specific heat capacity of Fe is 0.449 J/gC. Joe Chemist performs an experiment and find
the specific heat capacity for the Fe to be 0.598 J/gC. Joe’s percent error is
a) 33.2%
b) 3.32 %
c) 24.9 %
d) 0%
24. The phase change that occurs when a substance changes from a solid to a gas is called :
a) sublimation
b) deposition
c) supercooling
25. A solution is made by mixing 0.43 moles of A and 0.65 moles of B. The mole fraction of B is:
a) 0.40
b) 0.66
c) 1.51
d) crystallization
d) 0.56
26. Which of the following is true about a system at equilibrium?
a) the amounts of products and reactants are equal
b) the activation energy of the forward reaction is equal to the activation energy of the reverse reaction
c) the forward reaction is always exothermic
d) the rate of the forward reaction equals the rate of the reverse reaction
27. Which change will decrease the rate of the reaction between I2(s) and H2(g)?
(A)Increasing the partial pressure of H2(g)
(B)Adding the I2(s) as one piece rather than as several small ones
(C)Heating the reaction mixture
(D)Adding a catalyst for the reaction
28. Consider the system at equilibrium: 2SO2(g) + O2(g) 
the yield of SO3(g)?
I Increasing the temperature
II Increasing the volume of the container
(A) I only
(B) II only
2SO3(g) for which ∆H < 0. Which change(s) will increase
(C) Both I and II
(D) Neither I nor II
29. Consider the hypothetical reaction: A + 2B → C
The rate remains constant when the concentration of A is doubled and the concentration of B is held constant. The
reaction rate doubles when the concentration of B is doubled and the concentration of A is held constant. What are
the orders of A and B in this reaction?
(A) A = 0, B = 1
(B) A = 0, B = 2
(C) A = 1, B = 2
(D) A = 1, B = 0
30. Which one of the following mixtures creates a buffer solution?
(A) 10.0 mL 0.10 M NaOH, 10.0 mL 0.10 M HF
(B) 20.0 mL 0.10 M NaOH, 15.0 mL 0.10 M HF
(C) 15.0 mL 0.10 M NaOH, 20.0 mL 0.10 M HF
(D) 10.0 mL 0.10 M NaOH, 5.0 mL 0.20 M HF
31. A 0.015 M solution of a weak acid has a pH of 3.52. What is the value of the Ka for this acid?
(A)2.0 x 10–2
(B)6.2 x 10–6
(C)9.1 x 10–8
(D)1.4 x 10–9
32. Given the reactions:
CH4(g) → C (g) + 4H(g)
ΔH° = 1656 kJ•mol–1
HCCH(g) → 2C(g) + 2H(g)
ΔH° = 1648 kJ•mol–1
What is the estimated C C bond energy in kJ•mol–1?
(A)414
(B)820
(C)1234
(D)1664
33. What is the oxidation number of rhenium in Ca(ReO4)2?
(A)+1
(B)+3
(D)+7
(C)+6
34. What products result when aqueous solutions of CuCl2 and (NH4)2S are mixed?
(A) CuS(aq) and NH4Cl(s)
(B) CuS(s) and NH4Cl(aq)
(C) CuS(aq) and NH4Cl(g)
(D) CuS(s) and NH4Cl(s)
35. A chloride salt of rhenium contains 63.6% Re by mass. What is its empirical formula?
(A) ReCl
(B) ReCl2
(C) ReCl3
(D) ReCl5
36. A 1.50 mL sample of a sulfuric acid solution from an automobile storage battery is titrated with 1.47 M sodium
hydroxide solution to a phenolphthalein endpoint, requiring 23.70 mL. What is the molarity of the sulfuric acid?
(A) 23.2 M
(B) 11.6 M
(C) 6.30 M
(D) 0.181 M
37. Which terms are matched correctly?
(A) high vapor pressures high DHvap values
(C) low vapor pressure high boiling points
(B) high DHvap values low boiling points
(D) low boiling points low vaporization rates
38. Three balloons are filled with the same number of atoms of He, Ar, and Xe, respectively. Which statement is true
under the same conditions of temperature and pressure?
(A) The balloons contain the same mass of gas.
(B) All balloons have the same volume.
(C) The densities of the three gases are the same.
(D) The average speed of all the atoms is the same.
39. For the formation of one mole of each of these gases from their elements, which reaction is most endothermic?
(A) CO (ΔHf = –110.5 kJ·mol–1)
(B) NO2 (ΔHf = +33.9 kJ·mol–1)
–1
(C) O3 (ΔHf = +142.2 kJ·mol )
(D) SO2 (ΔHf = –300.4 kJ·mol–1)
40. A 0.239 g sample of a gas in a 100-mL flask exerts a pressure of 600 mmHg at 14 °C. What is the gas?
(A) chlorine
(B) nitrogen
(C) krypton
(D) xenon
41. The specific heats of several metals are given in the table below. If the same number of Joules were applied to the
same mass of each metal, which metal would show would show the greatest temperature change?
(A) Al
(B) Au
(C) Cu
(D) Hg
Metal
Al
Au
Cu
Hg
Specific Heat
0.900
0.129
0.385
0.139
42. When these substances are arranged in order of increasing S° values at 25 °C, what is the correct order?
(A) Na(s), Cl2(g), NaCl(s)
(B) NaCl(s), Cl2(g), Na(s)
(C) Cl2(g), NaCl(s), Na(s)
(D) Na(s), NaCl(s), Cl2(g)
43. In which process does the nitrogen undergo oxidation?
(A) N2  2NH3
(C) 2NO3–  N2O5
44. How many H atoms are in 3.4 g of C12H22O11?
(A) 6.0 × 1023
(B) 1.3 × 1023
(B) N2O4  2NO2
(D) NO2–  NO3
–
(C) 3.8 × 1022
(D) 6.0 × 1021
45. Ammonia is produced in accordance with this equation: N2(g) + 3H2(g) → 2NH3(g)
In a particular experiment, 0.25 mol of NH3 is formed when 0.5 mol of N2 is reacted with 0.5 mol of H2. What is
the percent yield?
(A) 75%
(B) 50%
(C) 33%
(D) 25%
46. Under which conditions will a gas behave most ideally?
(A) low P and high T
(C) high P and low T
(B) low P and low T
(D) high P and high T
Questions 47 and 48 should both be answered with reference to the reaction: 2NO(g) + O2(g)  2NO2(g), for which ΔHo
47. Which would increase the partial pressure of NO2(g) at equilibrium?
(A) decreasing the volume of the system
(B) adding a noble gas to increase the pressure of the system
(C) removing some NO(g) from the system
(D) adding an appropriate catalyst
48. At a certain temperature the equilibrium concentrations for this system are: [NO] = 0.52M; [O2] = 0.24M; [NO2] =
0.18M. What is the value of Kc at this temperature?
(A) 0.063
(B) 0.50
(C) 1.4
(D) 2.0
49. Which salt produces the most alkaline solution at a concentration of 0.1 M?
(A) KNO3
(B) MgCl2
(C) NH4Cl
(D) NaNO2
50. Which solute produces the highest boiling point in a 0.15m aqueous solution?
(A) CaCl2
(B) NaBr
(C) CuSO4
(D) CH3OH
PROBLEMS
1. For each of the following, indicate the type of reaction, predict the products, and balance.
a)
b)
Mg +
O2
FeS +
HCl


o
o
o
2. Using the Table below, calculate ∆G for the following reaction at 25 C, and state what the ∆ G value tells you
about the reaction:
2 H2 (g)
Substance
+
O2 (g) --------------> 2 H2O (g)
Δ Hf
H2O (g)
o
-242
(kJ/mole)
o
S (J/mole-K)
+ 189
O2 (g)
0
+ 205
H2 (g)
0
+ 131
3. Calculate the empirical formula of a compound having 32.48% sodium, 22.65% sulfur and 44.99 % oxygen.
4. For the following reaction that will proceed, (1) predict the products, (2) write and label the oxidation and
reduction half reactions, (3) write the net ionic equation, and (4) label the spectator ion(s).
Mg (s) +
HCl (aq)

5. Draw and label a diagram of the following electrochemical cell. Include all parts of the cell.
Ni (s)  Ni+2 (aq) ║ Cu+2 (aq) Cu (s)
Label the anode and cathode, and write the half reaction that takes place at each.
In which direction do the electrons flow?
6. Using the enthalpies of formation from thermochemical data, calculate the  H rxn for the combustion of ethane:
2
C2H6 (g) + 7 O2 (g) =======> 4 CO2 (g) + 6 H2O (l)
7. Given the reaction : H2 (g) + F2 (g) --------> 2 HF (g)
How many liters of HF will be formed if 66.0 grams of F2 react with an excess of hydrogen gas at STP?
8. For each of the unbalanced redox reactions below identify the atoms whose oxidation states are changing, which
process is oxidation and which is reduction, and the oxidizing agent and reducing agent.
MnO2 + KI + HCl
-------- > MnCl2
HgS + Cl-1
+ NO3-1
H2S + Br2
----------- >
+ KCl +
------------> HgCl4-2 + S +
I2
NO
S + HBr
9. Identify the following substances as acid, base, salt, or other and decide how each would be represented in an
aqueous solution
CaCO3
HF H2SO4
CO KBr ZnCl2
NaOH
Mg(OH)2
AgCl
KMnO4
HC2H3O2
HIO2
10. Calculate the amount of heat needed to heat 45.0 g of water from 12.0 C to 88.6 C.
11. How much heat is released when 367 g of water cool from 88.0C to 21.0C? The specific heat of water is 4.18
J/g.C.
12. At high temperatures, sulfur combines with iron to form the brown-black iron (II) sulfide:
Fe (s) + S (l)  FeS (s)
In one experiment, 7.62 g of Fe are allowed to react with 8.67 g of S.
a. What is the limiting reagent, and what is the reactant in excess?
b. Calculate the mass of FeS formed.
13. A chemist has two equal volumes of water. If he adds 1 mol of NaCl to one beaker and 1 mol of C6H12O6 to the
second beaker, which solution will have the higher boiling point. Explain.
14. Of the following substances, which ones are generally soluble in water
a. Ba3(PO4)2
b. Cu(NO3)2
c. Fe(OH)3
d. NH4C2H3O2
e. AgNO3
f. AgCl
g. K2SO4
15. What’s the % composition of Mg3N2
16. A compound contains 40.0% C, 6.7% H and 53.3 % O. The molar mass is 60.0 g/mol. Determine the empirical and molecular
formulas for the substance
17. Chlorine gas can be prepared according to the reaction
16 HCl + 2 KMnO4 → 5 Cl2 + 2 MnCl2 + 8 H2O
a. How many moles of MnCl2 can be produced when 25 g KMnO2 are mixed with 85 g HCl? Which reactant is the
limiting reactant?
b. What is the % yield if 10 g of MnCl2 is produced
c. How many grams of the excess reactant remains?
d.
18. For a solution of 0.025 M lactic acid, HC3H5O2 (Ka = 8.4 x 10-4), calculate
a. [H+]
b. pH
c. percent ionization
19. In the equation:
I2 + 5Cl2 + 6 H2O → 2HIO3 + 10 HCl
a.
b.
c.
d.
Which substance is oxidized
Which substance is reduced
What’s the oxidizing agent?
What’s the reducing agent?
20. Draw a galvanic (voltaic) cell for the following reaction: Ag + PbNO3 → AgNO3 + Pb. State the:
a. Anode
b. Cathode
c. Where oxidation occurs: show oxidation half-reaction
d. Where reduction occurs: show reduction half reaction
e. In which direction electrons flow through the wire
f. In which direction ions flow through the solution
21. Consider the following system at equilibrium:
SiF4(g) + 2H2O (g) ⇌ SiO2 (g) + 4 HF (g) ΔH=103.8 kJ
a. Is the reaction exothermic or endothermic?
b. If HF is added, in which direction will the equilibrium shift
c. If heat is added, in which direction will the equilibrium shift
d. If the pressure is increased, how will the equilibrium shift
e. A catalyst is added, how will the equilibrium shift
f. What’s the expression for Kc
22. One of the important pH-regulating systems in the blood consists of carbonic acid-sodium hydrogen carbonate buffer:
H2O3 (aq) ⇌ H+ (aq) + HCO3- (aq)
NaHCO3 → Na+ (aq) + HCO3- (aq)
Explain how this buffer resists changes in pH when excess OH- gets into the bloodstream
23. If it takes 0.048 g BaF2 to saturate 15.0 mL of water, what is the Ksp of BaF2?
24. Calculate the pH of an acetic acid buffer composed of HC2H3O2 (0.3M) and C2H3O2- (0.20M)
25. Calculate the pH and pOH of
a. Black coffee, 5.0 x 10-5 M H+
b. Limewater, 3.4 x 10-11 M H+
26. How do the kinetic-molecular theory account for the behavior of gases as described by
a. Boyle’s Law?
b. Charles’ Law?
c. Dalton’s Law of Partial Pressures?
27. When constant pressure is maintained, what effect does heating a mole of N 2 gas have on
a. Its density
b. Its mass
c. The average kinetic energy of its molecules
d. The average speed of its molecules
e. The number of N2 molecules in the sample
28. In the lab, students generated and collected oxygen gas according to the following equation:
2H2O2 (aq) 2 H2O (l) + O2 (g)
a. How many mL of oxygen gas at STP were generated from 50.0 g of H 2O2?
b. If 225 mL of oxygen gas at STP were needed for an experiment, how many moles of H 2O2 would be needed
29. A sample of gas occupies a volume of 525 mL at 625 torr. At constant temperature, what will be the new volume when the
pressure changes to 455 torr?
30. A 2.5-L sample of SO3 is at 19oC and 1.5 atm. What will be the new temperature in oC if the volume changes to 1.5 L and the
pressure to 765 torr?
31. Describe how you would prepare 750 mL of a 5.0 M NaCl solution
32. Why do salt trucks distribute salt over icy roads in the winter?
33. Which would be more effective in lowering the freezing point of 500 g of water? Why? Show calcs
a. 100 g of sucrose, C12H22O11 or 100 g of ethyl alcohol, C2H5OH
b. 100 g of NaCl or 100 g of CaCl2
34. Calculate the grams of solution in each of the following solutions
a. 2.5 L of 0.75 K2CrO4
b. 250 mL of a 16M HNO3
35. Suppose oxygen gas in a mixture of gases has a mole fraction of 0.498. If the total pressure is 1 atm, what is the partial
pressure of the oxygen gas?
36. Explain in terms of vapor pressure why the boiling point of a solution containing a nonvolatile solute is higher than that of
the pure solvent.
37. When 80.5 mL of 0.642 M Ba(NO3)2 are mixed with 44.5 mL of 0.743 M KOH, a precipitate of BA(OH) 2 forms. How many
grams of Ba(OH)2 do you expect?
38. Determine whether the following is a strong acid, strong base, weak acid, weak base: NH 3, HCl, KOH, HC2H3O2
39. Complete the following table
mL acid
37.19 HCl
48.04 H2SO4
13.13 H3PO4
Molarity acid
0.12 HCl
0.482 H2SO4
?
H3PO4
mL NaOH
31.91
?
39.39
Molarity NaOH
?
0.964
0.475
40. Complete and balance these equations. State the type of reaction as double displacement, single displacement, neutralization,
combustion:
a. Fe2O3 (s) + HBr (aq) 
b. Al (s) + H2SO4 (aq)
c. NaOH (aq) + H2CO3
d. K2O + HI
e. Ba(OH)2 + HClO4